Grate.



G. L. WALKER.

GRATE. APPLICATION FILED N0v.21, 19H. RENEWED JAN. 15.1917.

1,236,023. Patented Aug- 7,1917.

GEORGE. LESLIE W K 0 U BLQ. ee eae essen e e cam-HALF To wanes W. BROUGIITON, OF PUEBLO, COLORADO.

enA'r leteate A s- 7 91% Application filed November 27, 1911, Serial No. 6 ,62,682. Renewed January. 1 5, 1917. Serial No. 142,559.

To all whom it may concern:

Be it known that I, GEORGE LEsLm WVALKER, a citizen of the United States, residing at Pueblo, in the county of Pueblo. and State of Colorado, have invented a certain new and useful Improvement in Grates, of which the following is a full, clear, and exact description.

This invention is an improvement in grates designed for use in furnaces where coal is burned either for steam generation, or for the utilization in any other manner of the heat liberated by such combustion. The principal objects of my invention are to provide a grate on which the fuel will be more thoroughly and efliciently acted upon by the air; to so design the grate structurethat the air will be heated prior to coming into contact with the fuel; to provide means through which the amount of air admitted to the fire may be regulated by manipulation of the grate; and, withal, to so design the grate that it shall be simple and economical to construct. shall be capable of manufacture by casting, and shall not be easily injured or burned out in use.

It is a well recognized fact that if air can be successfully introduced into the fire in.

suflicient quantities in a lateral direction, as well as vertically, more complete and eflicient combustion will be obtained than on the flat type of grate now in use. This is for the reason that the path of the air through the bed of combustible is longer if it be introduced in horizontal direction, and the opportunity for the oxygen of the air to combine with the oxidizable elements of the fuel is correspondingly greater. I am aware that grates have hitherto been devised with the object of passing air into the fire in a direction other than vertically, but there are certain characteristics, absent in those proposed structures, which a grate must possess before it can successfully meet the requirements of practiceparticularly under steam boilers. A practical grate must be simple and cheap to construct, should be easyto mold and cast, and must not have small or intricate parts which will be easily burned out. My grate, further advantages of which will hereinafter appear in the specification, and be pointed out in the appended claims, is adapted to meet thQ requirements above mentioned, and also to accomplish the objects of invention set forth.

In the drawings, Figure 1 is a perspective of a. part of a grate constructed according to my invention; Fig. 2 is an end elevation of a pair of grate. bars, embodying a modified form of my invention, showing mechanism for. operating said bars; Fig. 3. is. a perspective of one of: the, leaves or teeth of which my grate bars may be built up; Fig. 4 is a plan view, showing a portion of: two grate, bars, constructed according to another. modification of my invention; and Fig. 5 is a perspective of a still further modification of the broad ideaof my invention.

For the sake of clearness of illustration I have shown my grate bars as built up of a series of leaves, or fingers, A, B, identically alike, but turned in different directions, and mounted on a square shaft, having round ends to. serve as trunnions. While I prefer to make the grate of these separate leaves so mounted, and shall describeit in that embodiment in this specification, it will be clearly evident that the entire grate may, if it is so desired, be cast as a unitarystructure, without in any way departing from my in-' vention. V

In Fig. 8 I have shown in detached view one of the leaves or teeth, which constitute the similar elements A, B, of my grate These elements are shaped somewhat like the letter Lone leg, marked a, being longer than the leg a and ending in a heel Z). The heel has a square opening 45" therein, thus adapting the leaf to fit on the square shaft 4, as clearly shown in Figs 1 and 2. In the preferred form the leaf is flattened at 9 to provide a substantially horizontal bed for a portion of the fuel; but I may omit this feature, and continue the planes of the tops of the legs a, a until they meet without departing from broad invention. I also prefer to bevel the top 2 of the heel Z), as shown in Fig. 3. i

In the form of grate shown in Fig. l, the leaves are mounted on square shaft 4 (which has rounded ends to serve as trunnions) and are separated from each other by liners 1. In this form the leaves A, B, are all mount ed so thatthe is inverted, but alternating on opposite sides of the shaft i. -so that the teeth are in staggered relation, "The Shafts 11 are so close together that the leaves of adjacent bars intermesh, resulting in a grate having ridges, which are termed pyramids, having ope-n sides and tops, and extending up into the bed of the fire between each pair of shafts.

In the modification shown in Fig. 2, the teeth A on one bar are inverted, and the teeth B are mounted in upright position,\ this order being reversed on the next adjacent bar, thus making a structure having alternate pyramids above and below the axial shafts 4, the pyramids above the shafts extending into the fire and those below the shafts inclosing a portion of the fire; each form, however, furnishing free access of air to the fuel from the sides.

The form shown in Fig. 5 is illustrative of a type in which the angle 9 (Fig. 3) is eliminated, and a leaf curved in an arc of a circle is substituted for that shaped as in Fig. 3. I have shown in this figure the curvature as circular, but it will be clear that teeth of other uniform curvature (as for instance that of the c'atenary) may be substituted therefor without departing from my invention.

It will be noted that in each of the modifications there is a transverse plane, which is vertical when the bars are in normal position, with respect to which the legs a, a are symmetrically disposed-aside from the asymmetry resulting from one of the legs being longer than the other. This is the plane in a uniformly curved tooth where the sign of the curvature changes with reference to the horizontal; and in a tooth 7 having a flattened portion 9 it is the central transverse plane through this flattened portion. This applies to the teeth whether in upright or inverted position and I have em ployed the term crown to refer to this plane.

The contour of leaves or teeth shown in Fig. 4 is adapted to be used with any of the modifications of Figs. 1, 2, or 5. In this figure the leaves are shown as having a thickened portion T around the crown. The function of this portion is to impede the vertical passage of air through the horizontal portion of the grate bar, thus forcing a greater percentage of air to pass through the sides of the pyramid and adding to the cross aeration of the fire.

Depending from the shafts 4, and formed as parts either of a liner 1, or of one of the leaves A, B, are arms 5, connected at their bottoms to a link 6 by pins 7 held in position by cotters 8. The link 6 is attached to a lever 10 by pin and cotter connection 11, 12. The lever 10 is fulcrumed at 14, where is also mounted the segment 15, provided with notches 16, 17, 17 18, and 18. A dog 19, pressed downwardly by the compression spring 20, and guided by the bracket 22, is normally in position to engage one of the notches in the segment. The dog 19 is connected at 21 to an actuating link 23, manipulated by a bell crank 24; by which the dog may be disengaged from the notches by gripping the bell crank 24. The lever 10 may then be shifted to rock the grate bars and move the leaves A, B, with relation to one another. This will produce a clearing action by which any clinker tending to form will be forced away from the grate. If the lever 10 be not returned to the intermediate position in which it is shown in Fig. 2, but be left in one of the side notches, the leaves will not be in as close relation, and the amount of air admitted to the fire will be increased. It will thus be seen that the draft on the grate may be regulated at will by manipulation of the grate itself. It is very desirable to have some means of adiusting the amount of air to be admitted to the grate to meet varying atmospheric conditions, or where, as frequently happens, the steaming qualities of an installation do not, for some reason, meet the requirements.

The manner of operation of my device is as follows, reference being had in particular to Fig. 1. The air entering from below is heated in the pockets formed by the curva ture of the leaves or teeth. It then passes between the leaves into the fire. 0n account of the peculiar shape of the grate, the path of a large percentage of the air through the fuel is in an inclined direction, more or less approximating the horizontal, and as the distance between adjacent pyramids is comparatively short, the mass of fuel lying there between is thoroughly exposed to the action of the blast. Some air will pass into the fire vertically (at the highest point 9 of the grate) but as the bed of fuel here is comparatively thin complete oxidation will take place also at that point. If it is desirable to still further reduce the percentage of air passing vertically through the fire, resort may be had to the expedient illustrated. in Fig. 4, where the spaces between adjacent teeth at the crown of the grate are decreased by thickening the teeth at that point. Cross aeration of the fire at its lowest point (that is over the spine or web) is assured by air passing under the lower points of the legs a, and the distance of these points from the spine is proportioned in such manner that sutlicient air is admitted for the complete combustion of the fuel lying on the spine.

The form shown in Fig. 2 also provides cross aeration at practically all points of the fire, and this form is adapted to cases where a deeper bed of fuel is desiredfor instance, in case lump coal is being burned.

In any form, if it is desired to admit more air, this can easily be efiected as stated above) by throwing the grate bars with relation to one another; By throwing the 1e-- ver 10 to the right allbars are rotated in: a clock-Wise direction, and? adjacent leaves in opposite direction; It the leaves do not lie in the same plane they offer less resistance to the passage of air, and thisresist ance may be varied at will by turning the bars a greater or" less distance:

In the claims Which form: apart" of this specification I: havereferred to theleaves or teeth of my grate as being L-shap'ed, but this should not be interpreted as meaning that the legs a and a must beat right angles toone another. On the contrary I intend this term to include all possibilities 0t shape from the slightest angularity which will give a sufiicient rise to the" grate to form a pyramid such as will give side draft, as described, to the form Where the anglebetween the legs-isvery acute. I alsointend this term to include the arc sha ped form shown -in Fig. 5 (which is the limit of the and all other curved teeth, such as sickle shaped, where the curvature of the teeth is the same throughout. I- further intend this term to' cover the tri-latera'l shaped teeth, similar to that illustrated in Fig. 3-, but where the flattened portions 9, 9 are elongated. The claims accompanying this application areto be interpreted in view of the meaning givento the expression L-sha'ped'by this paragraph.

Having thus described my invention, What I' claimand desire to se'cure by Letters'Patent is:

1. In a grate, a plurality of grate bars, each grate bar having aspine and a plurality of L-shaped teeth projecting," from said" spine, the teeth of each grate bar so intermeshing with those of the next adjacent grate bar that the outerend of each toothextends beyond the crown of the adjacent tooth on the adjacent grate bar.

2. In a grate, a plurality of grate bars, each grate-barhaving a spine and a plural ity of L-shaped teeth projecting from said spineout of the plane of the top'thereof, the teeth of each grate bar so intermeshing-withthose'of the next adjacent grate bar that the outer end of each tooth extends beyond the crown of the adjacent tooth onthe adjacent grate bar.

3. In a grate, a plurality of grate bars, each grate bar having a spine and aplural ity of L-shaped teeth projectin from said spine, the longer legof the h being" adjacent the spine and the teeth of each grate bar so intermeshing with those of the next adjacent grate bar that the outer end of each tooth extends beyond the crown of'the adjacent tooth on the adjacent grate-bar.

4. In a grate, a plurality of grate bars, each grate bar having a spine and a plural-- ity of L-shaped teeth projecting from said spine out of the plane of the top thereof, the longer leg of the ll. being adjacent the spine andthe teeth: oieach grate bar so intermeshing' with those of the next adjacent grate bar that the outer end of. each tooth extends beyond the crown of the adjacent tooth on the adjacent grate bar.

In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of L-shaped teeth projecting from said spine, the teeth of each grate bar so intermeshing with those of the next adjacent grate bar that their respective crowns lie in substantially the same vertical plane, thus forming a pyramid out of the plane of thegrate which pyram-idhas lateral and crown openings between adjacent teeth.

6. In a grate, a plurality of grate bars, eachz grate bar having a spine and a plurality of downwardly turned L-shaped teeth projecting upward from; the plane of the top of said spine, the teeth of each grate bar so inter-meshing with those of the next adjacent grate bar that their respective crowns lie in substantially the same vertical plane, thus: forming a pyramid above the plane of the top of the spine whichv has lateral and top openings between adjacent teeth.

7.. In a grate; a plurality of grate bars, each; grate bar having a spine and a plurality of l ..-shapcd teeth projecting from said spine, the longer leg of the L being. adjacent the spine", the teeth of each grate bar so intermeshing' with those of the next adjacent grate bar that their respective crowns lie in substantially the same vertical plane, thus forming a pyramid above the plane of the:

top of the spine which has lateral and top openings between.- adj-acent teeth.

8. In a grate, a plurality of grate bars,

each grate bar having a spine and a plurality of downwardly turned L-shaped' teeth projecting upward from the plane ot the top of said spine, the longer leg of the L being adjacent the spine and the teeth of each grate bar so interineshin-g with those of the next adjacent grate bar that their respective crowns-lie in substantially the same vertical plane, thus forminga pyramid above the'p'lane of? the "topof the spine. which has lateral and top: openings between adja cent teeth.

9. Ina grate, a series of grate" bars, bent teeth on said grate bars, said teeth intermeshi ng" with the teeth on adjacent gratebars to form a pyramid having lateral and crown openings therein, said pyramid extendingout of the planeof the top of the grate bar spines.

10. In a grate a series of grate bars, each grate barhavinga spine and L-shapedteeth projecting from the opposite sides thereof in staggered relation, the grate bars being so placed that the teeth on adjacent grate bars inter-mesh and the teeth being so shaped and proportioned that there is formed intermediate each pair of spines a single pyramid having lateral and crown openings.

11. In a grate, a plurality of grate bars having bent. teeth, the inner portion of each tooth making an angle with the horizontal and the outer portion of each tooth making asubstantially equal angle with the horizontal but in an opposite direction, the grate bars being so relatively placed that the teeth of each grate bar so intermesh with those of the next adjacent bar that the outer end of each tooth extends beyond the crown of the adjacent tooth on the adjacent grate bar.

12. In a grate, a plurality of grate bars having bent teeth, the inner portion of each tooth making an angle with the horizontal and the outer portion of each tooth making a substantially equal angle with the horizontal but in an opposite direction and the outer portion of the teeth being shorter than the inner, the grate bars being so relatively placed that the teeth of each grate bar so intermesh with those of the next adjacent bar that the outer end of each tooth extends beyond the crown of the adjacent tooth on the adjacent grate bar.

13. In a grate, a series of grate bars, each grate bar being composed of a spine and a plurality of L-shaped teeth projecting therefrom, the grate bars being so spaced that the teeth on adjacent grate bars intermesh and the teeth being so shaped and proportioned as to cooperate in forming, interme diate the axes of each pair of adjacent grate bars, a pyramid having lateral and crown openings, a single tooth serving to form a portion of opposite side walls of each pyramid.

1 1. In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of L-shaped teeth, having a horizontally thickened portion adjacent the angle of said L, projecting from said spine, the teeth of each grate bar intermeshing with those of the next adjacent grate bar with the thickened portions of adjacent teeth in substantial alinement.

15. In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of Lshaped teeth, having a horizontally thickened portion adjacent the angle of said L, projecting from said spine, the longer leg of the L being adjacent the spine, and the teeth of each grate bar intermeshing with those of thevnext adjacent grate bar with the thickened portions of adjacent teeth in substantial alinement.

16. In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of L-shaped teeth projecting from said spine, said teeth having a horizontally thickened portion adjacent the angle of said L, the teeth of each grate bar intermes g with those of the next adjacent grate bar and in substantial parallelism therewith, thus forming a pyramid above the plane of the top of the spine which has lateral and crown openings between adjacent teeth, the crown openings being narrower than the lateral openings.

17. In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of L-shaped teeth projecting from said spine, said teeth having a horizontally thickened portion adjacent the angle of said L, the longer leg of the L being adjacent the spine, the teeth of each grate bar intermeshing with those of the next adjacent grate bar and being in substantial parallelism therewith, thus forming a pyramid above the plane of the top of the spine which has lateral and crown openings between adjacent teeth, the crown openings being narrower than the lateral openings.

18. In a grate, a series of grate bars having bent teeth provided with a horizontally thickened portion adjacent the crown of said teeth, the grate teeth intermeshing with the teeth on adjacent grate bars to form a pyramid having lateral and crown openings therein, the crown openings being more restricted than the lateral openings, and said pyramid extending out of the plane of the top of the grate bar spines.

19. In a grate, a series of grate bars, each grate bar having a spine and L-shaped teeth projecting from the opposite sides thereof in staggered relation, the grate bars being so placed that the teeth on adjacent bars intermesh and the teeth being so shaped and proportioned that there is formed intermediate each pair of spines a pyramid having lateral and crown openings therein, the crown openings being more restricted than the lateral openings.

20. In a grate, a plurality of grate bars having bent intermeshing teeth, the inner portion of said teeth making an angle with the horizontal and the outer portion of said teeth making an approximately equal angle with the horizontal but in an opposite direction, the teeth being wider at the junction between the inner and outer portions than in other parts.

21. In a grate, a plurality of grate bars having bent intermeshing teeth, the inner portion of said teeth making an angle-with the horizontal and the outer portion of said teeth making an approximately equal angle with the horizontal but in an opposite direction, the outer portion of the teeth being shorter than the inner and the teeth being wider at the junction between the inner and outer portions than in other parts.

22. Ina grate, a plurality of grate bars having bent teeth and the teeth of each grate bar so intermeshing with those of the ne t dj n g te bar h t their r p ctive crowns lie in substantially the same vertical plane, and means for shifting the angular relation of the teeth of adjacent grate bars to vary the amount of air passing through the grate.

23. In a grate, a series of grate bars, bent teeth on said grate bars, said teeth intermeshing with the teeth on adjacent grate bars to form a pyramid having lateral and crown openings therein, and means for shifting the angular relation of the teeth of adjacent grate bars to vary the amount of air passing through the grate.

24. In a grate, a plurality of grate bars, each grate bar having a spine and a plurality of L-shaped teeth projecting from said spine, the teeth of each grate bar so intermeshing with those of the next adjacent grate bar that the outer end of each tooth extends beyond the crown of the adjacent tooth on the adjacent grate bar, an arm depending from each spine, a link connecting said arms and joined at its outer end to a lever, in combination with means for retaining the lever in varying angular position, whereby the grate bars may be rocked to vary the relative position of the grate bar teeth and the amount of air admitted to the fire.

In testimony whereof I hereunto atfix my signature in the presence of two witnesses.

GEORGE LESLIE WALKER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

